kernel/trace/trace_output.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * trace_output.c
   4  *
   5  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   6  *
   7  */
   8 #include <linux/module.h>
   9 #include <linux/mutex.h>
  10 #include <linux/ftrace.h>
  11 #include <linux/sched/clock.h>
  12 #include <linux/sched/mm.h>
  13
  14 #include "trace_output.h"
  15
  16 /* must be a power of 2 */
  17 #define EVENT_HASHSIZE  128
  18
  19 DECLARE_RWSEM(trace_event_sem);
  20
  21 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  22
  23 static int next_event_type = __TRACE_LAST_TYPE + 1;
  24
  25 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  26 {
  27         struct trace_seq *s = &iter->seq;
  28         struct trace_entry *entry = iter->ent;
  29         struct bputs_entry *field;
  30
  31         trace_assign_type(field, entry);
  32
  33         trace_seq_puts(s, field->str);
  34
  35         return trace_handle_return(s);
  36 }
  37
  38 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  39 {
  40         struct trace_seq *s = &iter->seq;
  41         struct trace_entry *entry = iter->ent;
  42         struct bprint_entry *field;
  43
  44         trace_assign_type(field, entry);
  45
  46         trace_seq_bprintf(s, field->fmt, field->buf);
  47
  48         return trace_handle_return(s);
  49 }
  50
  51 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  52 {
  53         struct trace_seq *s = &iter->seq;
  54         struct trace_entry *entry = iter->ent;
  55         struct print_entry *field;
  56
  57         trace_assign_type(field, entry);
  58
  59         trace_seq_puts(s, field->buf);
  60
  61         return trace_handle_return(s);
  62 }
  63
  64 const char *
  65 trace_print_flags_seq(struct trace_seq *p, const char *delim,
  66                       unsigned long flags,
  67                       const struct trace_print_flags *flag_array)
  68 {
  69         unsigned long mask;
  70         const char *str;
  71         const char *ret = trace_seq_buffer_ptr(p);
  72         int i, first = 1;
  73
  74         for (i = 0;  flag_array[i].name && flags; i++) {
  75
  76                 mask = flag_array[i].mask;
  77                 if ((flags & mask) != mask)
  78                         continue;
  79
  80                 str = flag_array[i].name;
  81                 flags &= ~mask;
  82                 if (!first && delim)
  83                         trace_seq_puts(p, delim);
  84                 else
  85                         first = 0;
  86                 trace_seq_puts(p, str);
  87         }
  88
  89         /* check for left over flags */
  90         if (flags) {
  91                 if (!first && delim)
  92                         trace_seq_puts(p, delim);
  93                 trace_seq_printf(p, "0x%lx", flags);
  94         }
  95
  96         trace_seq_putc(p, 0);
  97
  98         return ret;
  99 }
 100 EXPORT_SYMBOL(trace_print_flags_seq);
 101
 102 const char *
 103 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 104                         const struct trace_print_flags *symbol_array)
 105 {
 106         int i;
 107         const char *ret = trace_seq_buffer_ptr(p);
 108
 109         for (i = 0;  symbol_array[i].name; i++) {
 110
 111                 if (val != symbol_array[i].mask)
 112                         continue;
 113
 114                 trace_seq_puts(p, symbol_array[i].name);
 115                 break;
 116         }
 117
 118         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 119                 trace_seq_printf(p, "0x%lx", val);
 120
 121         trace_seq_putc(p, 0);
 122
 123         return ret;
 124 }
 125 EXPORT_SYMBOL(trace_print_symbols_seq);
 126
 127 #if BITS_PER_LONG == 32
 128 const char *
 129 trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
 130                       unsigned long long flags,
 131                       const struct trace_print_flags_u64 *flag_array)
 132 {
 133         unsigned long long mask;
 134         const char *str;
 135         const char *ret = trace_seq_buffer_ptr(p);
 136         int i, first = 1;
 137
 138         for (i = 0;  flag_array[i].name && flags; i++) {
 139
 140                 mask = flag_array[i].mask;
 141                 if ((flags & mask) != mask)
 142                         continue;
 143
 144                 str = flag_array[i].name;
 145                 flags &= ~mask;
 146                 if (!first && delim)
 147                         trace_seq_puts(p, delim);
 148                 else
 149                         first = 0;
 150                 trace_seq_puts(p, str);
 151         }
 152
 153         /* check for left over flags */
 154         if (flags) {
 155                 if (!first && delim)
 156                         trace_seq_puts(p, delim);
 157                 trace_seq_printf(p, "0x%llx", flags);
 158         }
 159
 160         trace_seq_putc(p, 0);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL(trace_print_flags_seq_u64);
 165
 166 const char *
 167 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 168                          const struct trace_print_flags_u64 *symbol_array)
 169 {
 170         int i;
 171         const char *ret = trace_seq_buffer_ptr(p);
 172
 173         for (i = 0;  symbol_array[i].name; i++) {
 174
 175                 if (val != symbol_array[i].mask)
 176                         continue;
 177
 178                 trace_seq_puts(p, symbol_array[i].name);
 179                 break;
 180         }
 181
 182         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 183                 trace_seq_printf(p, "0x%llx", val);
 184
 185         trace_seq_putc(p, 0);
 186
 187         return ret;
 188 }
 189 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 190 #endif
 191
 192 const char *
 193 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 194                         unsigned int bitmask_size)
 195 {
 196         const char *ret = trace_seq_buffer_ptr(p);
 197
 198         trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 199         trace_seq_putc(p, 0);
 200
 201         return ret;
 202 }
 203 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 204
 205 /**
 206  * trace_print_hex_seq - print buffer as hex sequence
 207  * @p: trace seq struct to write to
 208  * @buf: The buffer to print
 209  * @buf_len: Length of @buf in bytes
 210  * @concatenate: Print @buf as single hex string or with spacing
 211  *
 212  * Prints the passed buffer as a hex sequence either as a whole,
 213  * single hex string if @concatenate is true or with spacing after
 214  * each byte in case @concatenate is false.
 215  */
 216 const char *
 217 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 218                     bool concatenate)
 219 {
 220         int i;
 221         const char *ret = trace_seq_buffer_ptr(p);
 222
 223         for (i = 0; i < buf_len; i++)
 224                 trace_seq_printf(p, "%s%2.2x", concatenate || i == 0 ? "" : " ",
 225                                  buf[i]);
 226         trace_seq_putc(p, 0);
 227
 228         return ret;
 229 }
 230 EXPORT_SYMBOL(trace_print_hex_seq);
 231
 232 const char *
 233 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 234                       size_t el_size)
 235 {
 236         const char *ret = trace_seq_buffer_ptr(p);
 237         const char *prefix = "";
 238         void *ptr = (void *)buf;
 239         size_t buf_len = count * el_size;
 240
 241         trace_seq_putc(p, '{');
 242
 243         while (ptr < buf + buf_len) {
 244                 switch (el_size) {
 245                 case 1:
 246                         trace_seq_printf(p, "%s0x%x", prefix,
 247                                          *(u8 *)ptr);
 248                         break;
 249                 case 2:
 250                         trace_seq_printf(p, "%s0x%x", prefix,
 251                                          *(u16 *)ptr);
 252                         break;
 253                 case 4:
 254                         trace_seq_printf(p, "%s0x%x", prefix,
 255                                          *(u32 *)ptr);
 256                         break;
 257                 case 8:
 258                         trace_seq_printf(p, "%s0x%llx", prefix,
 259                                          *(u64 *)ptr);
 260                         break;
 261                 default:
 262                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 263                                          *(u8 *)ptr);
 264                         el_size = 1;
 265                 }
 266                 prefix = ",";
 267                 ptr += el_size;
 268         }
 269
 270         trace_seq_putc(p, '}');
 271         trace_seq_putc(p, 0);
 272
 273         return ret;
 274 }
 275 EXPORT_SYMBOL(trace_print_array_seq);
 276
 277 int trace_raw_output_prep(struct trace_iterator *iter,
 278                           struct trace_event *trace_event)
 279 {
 280         struct trace_event_call *event;
 281         struct trace_seq *s = &iter->seq;
 282         struct trace_seq *p = &iter->tmp_seq;
 283         struct trace_entry *entry;
 284
 285         event = container_of(trace_event, struct trace_event_call, event);
 286         entry = iter->ent;
 287
 288         if (entry->type != event->event.type) {
 289                 WARN_ON_ONCE(1);
 290                 return TRACE_TYPE_UNHANDLED;
 291         }
 292
 293         trace_seq_init(p);
 294         trace_seq_printf(s, "%s: ", trace_event_name(event));
 295
 296         return trace_handle_return(s);
 297 }
 298 EXPORT_SYMBOL(trace_raw_output_prep);
 299
 300 static int trace_output_raw(struct trace_iterator *iter, char *name,
 301                             char *fmt, va_list ap)
 302 {
 303         struct trace_seq *s = &iter->seq;
 304
 305         trace_seq_printf(s, "%s: ", name);
 306         trace_seq_vprintf(s, fmt, ap);
 307
 308         return trace_handle_return(s);
 309 }
 310
 311 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 312 {
 313         va_list ap;
 314         int ret;
 315
 316         va_start(ap, fmt);
 317         ret = trace_output_raw(iter, name, fmt, ap);
 318         va_end(ap);
 319
 320         return ret;
 321 }
 322 EXPORT_SYMBOL_GPL(trace_output_call);
 323
 324 #ifdef CONFIG_KRETPROBES
 325 static inline const char *kretprobed(const char *name)
 326 {
 327         static const char tramp_name[] = "kretprobe_trampoline";
 328         int size = sizeof(tramp_name);
 329
 330         if (strncmp(tramp_name, name, size) == 0)
 331                 return "[unknown/kretprobe'd]";
 332         return name;
 333 }
 334 #else
 335 static inline const char *kretprobed(const char *name)
 336 {
 337         return name;
 338 }
 339 #endif /* CONFIG_KRETPROBES */
 340
 341 static void
 342 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 343 {
 344         char str[KSYM_SYMBOL_LEN];
 345 #ifdef CONFIG_KALLSYMS
 346         const char *name;
 347
 348         kallsyms_lookup(address, NULL, NULL, NULL, str);
 349
 350         name = kretprobed(str);
 351
 352         if (name && strlen(name)) {
 353                 trace_seq_printf(s, fmt, name);
 354                 return;
 355         }
 356 #endif
 357         snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address);
 358         trace_seq_printf(s, fmt, str);
 359 }
 360
 361 static void
 362 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 363                      unsigned long address)
 364 {
 365         char str[KSYM_SYMBOL_LEN];
 366 #ifdef CONFIG_KALLSYMS
 367         const char *name;
 368
 369         sprint_symbol(str, address);
 370         name = kretprobed(str);
 371
 372         if (name && strlen(name)) {
 373                 trace_seq_printf(s, fmt, name);
 374                 return;
 375         }
 376 #endif
 377         snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address);
 378         trace_seq_printf(s, fmt, str);
 379 }
 380
 381 #ifndef CONFIG_64BIT
 382 # define IP_FMT "%08lx"
 383 #else
 384 # define IP_FMT "%016lx"
 385 #endif
 386
 387 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 388                              unsigned long ip, unsigned long sym_flags)
 389 {
 390         struct file *file = NULL;
 391         unsigned long vmstart = 0;
 392         int ret = 1;
 393
 394         if (s->full)
 395                 return 0;
 396
 397         if (mm) {
 398                 const struct vm_area_struct *vma;
 399
 400                 down_read(&mm->mmap_sem);
 401                 vma = find_vma(mm, ip);
 402                 if (vma) {
 403                         file = vma->vm_file;
 404                         vmstart = vma->vm_start;
 405                 }
 406                 if (file) {
 407                         ret = trace_seq_path(s, &file->f_path);
 408                         if (ret)
 409                                 trace_seq_printf(s, "[+0x%lx]",
 410                                                  ip - vmstart);
 411                 }
 412                 up_read(&mm->mmap_sem);
 413         }
 414         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 415                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 416         return !trace_seq_has_overflowed(s);
 417 }
 418
 419 int
 420 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 421 {
 422         if (!ip) {
 423                 trace_seq_putc(s, '0');
 424                 goto out;
 425         }
 426
 427         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 428                 seq_print_sym_offset(s, "%s", ip);
 429         else
 430                 seq_print_sym_short(s, "%s", ip);
 431
 432         if (sym_flags & TRACE_ITER_SYM_ADDR)
 433                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 434
 435  out:
 436         return !trace_seq_has_overflowed(s);
 437 }
 438
 439 /**
 440  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 441  * @s: trace seq struct to write to
 442  * @entry: The trace entry field from the ring buffer
 443  *
 444  * Prints the generic fields of irqs off, in hard or softirq, preempt
 445  * count.
 446  */
 447 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 448 {
 449         char hardsoft_irq;
 450         char need_resched;
 451         char irqs_off;
 452         int hardirq;
 453         int softirq;
 454         int nmi;
 455
 456         nmi = entry->flags & TRACE_FLAG_NMI;
 457         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 458         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 459
 460         irqs_off =
 461                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 462                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 463                 '.';
 464
 465         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 466                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 467         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 468                 need_resched = 'N';
 469                 break;
 470         case TRACE_FLAG_NEED_RESCHED:
 471                 need_resched = 'n';
 472                 break;
 473         case TRACE_FLAG_PREEMPT_RESCHED:
 474                 need_resched = 'p';
 475                 break;
 476         default:
 477                 need_resched = '.';
 478                 break;
 479         }
 480
 481         hardsoft_irq =
 482                 (nmi && hardirq)     ? 'Z' :
 483                 nmi                  ? 'z' :
 484                 (hardirq && softirq) ? 'H' :
 485                 hardirq              ? 'h' :
 486                 softirq              ? 's' :
 487                                        '.' ;
 488
 489         trace_seq_printf(s, "%c%c%c",
 490                          irqs_off, need_resched, hardsoft_irq);
 491
 492         if (entry->preempt_count)
 493                 trace_seq_printf(s, "%x", entry->preempt_count);
 494         else
 495                 trace_seq_putc(s, '.');
 496
 497         return !trace_seq_has_overflowed(s);
 498 }
 499
 500 static int
 501 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 502 {
 503         char comm[TASK_COMM_LEN];
 504
 505         trace_find_cmdline(entry->pid, comm);
 506
 507         trace_seq_printf(s, "%8.8s-%-5d %3d",
 508                          comm, entry->pid, cpu);
 509
 510         return trace_print_lat_fmt(s, entry);
 511 }
 512
 513 #undef MARK
 514 #define MARK(v, s) {.val = v, .sym = s}
 515 /* trace overhead mark */
 516 static const struct trace_mark {
 517         unsigned long long      val; /* unit: nsec */
 518         char                    sym;
 519 } mark[] = {
 520         MARK(1000000000ULL      , '$'), /* 1 sec */
 521         MARK(100000000ULL       , '@'), /* 100 msec */
 522         MARK(10000000ULL        , '*'), /* 10 msec */
 523         MARK(1000000ULL         , '#'), /* 1000 usecs */
 524         MARK(100000ULL          , '!'), /* 100 usecs */
 525         MARK(10000ULL           , '+'), /* 10 usecs */
 526 };
 527 #undef MARK
 528
 529 char trace_find_mark(unsigned long long d)
 530 {
 531         int i;
 532         int size = ARRAY_SIZE(mark);
 533
 534         for (i = 0; i < size; i++) {
 535                 if (d > mark[i].val)
 536                         break;
 537         }
 538
 539         return (i == size) ? ' ' : mark[i].sym;
 540 }
 541
 542 static int
 543 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 544 {
 545         struct trace_array *tr = iter->tr;
 546         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 547         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 548         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 549         unsigned long long rel_ts = next_ts - iter->ts;
 550         struct trace_seq *s = &iter->seq;
 551
 552         if (in_ns) {
 553                 abs_ts = ns2usecs(abs_ts);
 554                 rel_ts = ns2usecs(rel_ts);
 555         }
 556
 557         if (verbose && in_ns) {
 558                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 559                 unsigned long abs_msec = (unsigned long)abs_ts;
 560                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 561                 unsigned long rel_msec = (unsigned long)rel_ts;
 562
 563                 trace_seq_printf(
 564                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 565                         ns2usecs(iter->ts),
 566                         abs_msec, abs_usec,
 567                         rel_msec, rel_usec);
 568
 569         } else if (verbose && !in_ns) {
 570                 trace_seq_printf(
 571                         s, "[%016llx] %lld (+%lld): ",
 572                         iter->ts, abs_ts, rel_ts);
 573
 574         } else if (!verbose && in_ns) {
 575                 trace_seq_printf(
 576                         s, " %4lldus%c: ",
 577                         abs_ts,
 578                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 579
 580         } else { /* !verbose && !in_ns */
 581                 trace_seq_printf(s, " %4lld: ", abs_ts);
 582         }
 583
 584         return !trace_seq_has_overflowed(s);
 585 }
 586
 587 int trace_print_context(struct trace_iterator *iter)
 588 {
 589         struct trace_array *tr = iter->tr;
 590         struct trace_seq *s = &iter->seq;
 591         struct trace_entry *entry = iter->ent;
 592         unsigned long long t;
 593         unsigned long secs, usec_rem;
 594         char comm[TASK_COMM_LEN];
 595
 596         trace_find_cmdline(entry->pid, comm);
 597
 598         trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
 599
 600         if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
 601                 unsigned int tgid = trace_find_tgid(entry->pid);
 602
 603                 if (!tgid)
 604                         trace_seq_printf(s, "(-----) ");
 605                 else
 606                         trace_seq_printf(s, "(%5d) ", tgid);
 607         }
 608
 609         trace_seq_printf(s, "[%03d] ", iter->cpu);
 610
 611         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 612                 trace_print_lat_fmt(s, entry);
 613
 614         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 615                 t = ns2usecs(iter->ts);
 616                 usec_rem = do_div(t, USEC_PER_SEC);
 617                 secs = (unsigned long)t;
 618                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 619         } else
 620                 trace_seq_printf(s, " %12llu: ", iter->ts);
 621
 622         return !trace_seq_has_overflowed(s);
 623 }
 624
 625 int trace_print_lat_context(struct trace_iterator *iter)
 626 {
 627         struct trace_array *tr = iter->tr;
 628         /* trace_find_next_entry will reset ent_size */
 629         int ent_size = iter->ent_size;
 630         struct trace_seq *s = &iter->seq;
 631         u64 next_ts;
 632         struct trace_entry *entry = iter->ent,
 633                            *next_entry = trace_find_next_entry(iter, NULL,
 634                                                                &next_ts);
 635         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 636
 637         /* Restore the original ent_size */
 638         iter->ent_size = ent_size;
 639
 640         if (!next_entry)
 641                 next_ts = iter->ts;
 642
 643         if (verbose) {
 644                 char comm[TASK_COMM_LEN];
 645
 646                 trace_find_cmdline(entry->pid, comm);
 647
 648                 trace_seq_printf(
 649                         s, "%16s %5d %3d %d %08x %08lx ",
 650                         comm, entry->pid, iter->cpu, entry->flags,
 651                         entry->preempt_count, iter->idx);
 652         } else {
 653                 lat_print_generic(s, entry, iter->cpu);
 654         }
 655
 656         lat_print_timestamp(iter, next_ts);
 657
 658         return !trace_seq_has_overflowed(s);
 659 }
 660
 661 /**
 662  * ftrace_find_event - find a registered event
 663  * @type: the type of event to look for
 664  *
 665  * Returns an event of type @type otherwise NULL
 666  * Called with trace_event_read_lock() held.
 667  */
 668 struct trace_event *ftrace_find_event(int type)
 669 {
 670         struct trace_event *event;
 671         unsigned key;
 672
 673         key = type & (EVENT_HASHSIZE - 1);
 674
 675         hlist_for_each_entry(event, &event_hash[key], node) {
 676                 if (event->type == type)
 677                         return event;
 678         }
 679
 680         return NULL;
 681 }
 682
 683 static LIST_HEAD(ftrace_event_list);
 684
 685 static int trace_search_list(struct list_head **list)
 686 {
 687         struct trace_event *e;
 688         int last = __TRACE_LAST_TYPE;
 689
 690         if (list_empty(&ftrace_event_list)) {
 691                 *list = &ftrace_event_list;
 692                 return last + 1;
 693         }
 694
 695         /*
 696          * We used up all possible max events,
 697          * lets see if somebody freed one.
 698          */
 699         list_for_each_entry(e, &ftrace_event_list, list) {
 700                 if (e->type != last + 1)
 701                         break;
 702                 last++;
 703         }
 704
 705         /* Did we used up all 65 thousand events??? */
 706         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 707                 return 0;
 708
 709         *list = &e->list;
 710         return last + 1;
 711 }
 712
 713 void trace_event_read_lock(void)
 714 {
 715         down_read(&trace_event_sem);
 716 }
 717
 718 void trace_event_read_unlock(void)
 719 {
 720         up_read(&trace_event_sem);
 721 }
 722
 723 /**
 724  * register_trace_event - register output for an event type
 725  * @event: the event type to register
 726  *
 727  * Event types are stored in a hash and this hash is used to
 728  * find a way to print an event. If the @event->type is set
 729  * then it will use that type, otherwise it will assign a
 730  * type to use.
 731  *
 732  * If you assign your own type, please make sure it is added
 733  * to the trace_type enum in trace.h, to avoid collisions
 734  * with the dynamic types.
 735  *
 736  * Returns the event type number or zero on error.
 737  */
 738 int register_trace_event(struct trace_event *event)
 739 {
 740         unsigned key;
 741         int ret = 0;
 742
 743         down_write(&trace_event_sem);
 744
 745         if (WARN_ON(!event))
 746                 goto out;
 747
 748         if (WARN_ON(!event->funcs))
 749                 goto out;
 750
 751         INIT_LIST_HEAD(&event->list);
 752
 753         if (!event->type) {
 754                 struct list_head *list = NULL;
 755
 756                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 757
 758                         event->type = trace_search_list(&list);
 759                         if (!event->type)
 760                                 goto out;
 761
 762                 } else {
 763
 764                         event->type = next_event_type++;
 765                         list = &ftrace_event_list;
 766                 }
 767
 768                 if (WARN_ON(ftrace_find_event(event->type)))
 769                         goto out;
 770
 771                 list_add_tail(&event->list, list);
 772
 773         } else if (event->type > __TRACE_LAST_TYPE) {
 774                 printk(KERN_WARNING "Need to add type to trace.h\n");
 775                 WARN_ON(1);
 776                 goto out;
 777         } else {
 778                 /* Is this event already used */
 779                 if (ftrace_find_event(event->type))
 780                         goto out;
 781         }
 782
 783         if (event->funcs->trace == NULL)
 784                 event->funcs->trace = trace_nop_print;
 785         if (event->funcs->raw == NULL)
 786                 event->funcs->raw = trace_nop_print;
 787         if (event->funcs->hex == NULL)
 788                 event->funcs->hex = trace_nop_print;
 789         if (event->funcs->binary == NULL)
 790                 event->funcs->binary = trace_nop_print;
 791
 792         key = event->type & (EVENT_HASHSIZE - 1);
 793
 794         hlist_add_head(&event->node, &event_hash[key]);
 795
 796         ret = event->type;
 797  out:
 798         up_write(&trace_event_sem);
 799
 800         return ret;
 801 }
 802 EXPORT_SYMBOL_GPL(register_trace_event);
 803
 804 /*
 805  * Used by module code with the trace_event_sem held for write.
 806  */
 807 int __unregister_trace_event(struct trace_event *event)
 808 {
 809         hlist_del(&event->node);
 810         list_del(&event->list);
 811         return 0;
 812 }
 813
 814 /**
 815  * unregister_trace_event - remove a no longer used event
 816  * @event: the event to remove
 817  */
 818 int unregister_trace_event(struct trace_event *event)
 819 {
 820         down_write(&trace_event_sem);
 821         __unregister_trace_event(event);
 822         up_write(&trace_event_sem);
 823
 824         return 0;
 825 }
 826 EXPORT_SYMBOL_GPL(unregister_trace_event);
 827
 828 /*
 829  * Standard events
 830  */
 831
 832 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 833                                   struct trace_event *event)
 834 {
 835         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 836
 837         return trace_handle_return(&iter->seq);
 838 }
 839
 840 /* TRACE_FN */
 841 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 842                                         struct trace_event *event)
 843 {
 844         struct ftrace_entry *field;
 845         struct trace_seq *s = &iter->seq;
 846
 847         trace_assign_type(field, iter->ent);
 848
 849         seq_print_ip_sym(s, field->ip, flags);
 850
 851         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 852                 trace_seq_puts(s, " <-");
 853                 seq_print_ip_sym(s, field->parent_ip, flags);
 854         }
 855
 856         trace_seq_putc(s, '\n');
 857
 858         return trace_handle_return(s);
 859 }
 860
 861 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 862                                       struct trace_event *event)
 863 {
 864         struct ftrace_entry *field;
 865
 866         trace_assign_type(field, iter->ent);
 867
 868         trace_seq_printf(&iter->seq, "%lx %lx\n",
 869                          field->ip,
 870                          field->parent_ip);
 871
 872         return trace_handle_return(&iter->seq);
 873 }
 874
 875 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 876                                       struct trace_event *event)
 877 {
 878         struct ftrace_entry *field;
 879         struct trace_seq *s = &iter->seq;
 880
 881         trace_assign_type(field, iter->ent);
 882
 883         SEQ_PUT_HEX_FIELD(s, field->ip);
 884         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 885
 886         return trace_handle_return(s);
 887 }
 888
 889 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 890                                       struct trace_event *event)
 891 {
 892         struct ftrace_entry *field;
 893         struct trace_seq *s = &iter->seq;
 894
 895         trace_assign_type(field, iter->ent);
 896
 897         SEQ_PUT_FIELD(s, field->ip);
 898         SEQ_PUT_FIELD(s, field->parent_ip);
 899
 900         return trace_handle_return(s);
 901 }
 902
 903 static struct trace_event_functions trace_fn_funcs = {
 904         .trace          = trace_fn_trace,
 905         .raw            = trace_fn_raw,
 906         .hex            = trace_fn_hex,
 907         .binary         = trace_fn_bin,
 908 };
 909
 910 static struct trace_event trace_fn_event = {
 911         .type           = TRACE_FN,
 912         .funcs          = &trace_fn_funcs,
 913 };
 914
 915 /* TRACE_CTX an TRACE_WAKE */
 916 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 917                                              char *delim)
 918 {
 919         struct ctx_switch_entry *field;
 920         char comm[TASK_COMM_LEN];
 921         int S, T;
 922
 923
 924         trace_assign_type(field, iter->ent);
 925
 926         T = task_index_to_char(field->next_state);
 927         S = task_index_to_char(field->prev_state);
 928         trace_find_cmdline(field->next_pid, comm);
 929         trace_seq_printf(&iter->seq,
 930                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 931                          field->prev_pid,
 932                          field->prev_prio,
 933                          S, delim,
 934                          field->next_cpu,
 935                          field->next_pid,
 936                          field->next_prio,
 937                          T, comm);
 938
 939         return trace_handle_return(&iter->seq);
 940 }
 941
 942 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 943                                          struct trace_event *event)
 944 {
 945         return trace_ctxwake_print(iter, "==>");
 946 }
 947
 948 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 949                                           int flags, struct trace_event *event)
 950 {
 951         return trace_ctxwake_print(iter, "  +");
 952 }
 953
 954 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 955 {
 956         struct ctx_switch_entry *field;
 957         int T;
 958
 959         trace_assign_type(field, iter->ent);
 960
 961         if (!S)
 962                 S = task_index_to_char(field->prev_state);
 963         T = task_index_to_char(field->next_state);
 964         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 965                          field->prev_pid,
 966                          field->prev_prio,
 967                          S,
 968                          field->next_cpu,
 969                          field->next_pid,
 970                          field->next_prio,
 971                          T);
 972
 973         return trace_handle_return(&iter->seq);
 974 }
 975
 976 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 977                                        struct trace_event *event)
 978 {
 979         return trace_ctxwake_raw(iter, 0);
 980 }
 981
 982 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 983                                         struct trace_event *event)
 984 {
 985         return trace_ctxwake_raw(iter, '+');
 986 }
 987
 988
 989 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 990 {
 991         struct ctx_switch_entry *field;
 992         struct trace_seq *s = &iter->seq;
 993         int T;
 994
 995         trace_assign_type(field, iter->ent);
 996
 997         if (!S)
 998                 S = task_index_to_char(field->prev_state);
 999         T = task_index_to_char(field->next_state);
1000
1001         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
1002         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
1003         SEQ_PUT_HEX_FIELD(s, S);
1004         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
1005         SEQ_PUT_HEX_FIELD(s, field->next_pid);
1006         SEQ_PUT_HEX_FIELD(s, field->next_prio);
1007         SEQ_PUT_HEX_FIELD(s, T);
1008
1009         return trace_handle_return(s);
1010 }
1011
1012 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1013                                        struct trace_event *event)
1014 {
1015         return trace_ctxwake_hex(iter, 0);
1016 }
1017
1018 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1019                                         struct trace_event *event)
1020 {
1021         return trace_ctxwake_hex(iter, '+');
1022 }
1023
1024 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1025                                            int flags, struct trace_event *event)
1026 {
1027         struct ctx_switch_entry *field;
1028         struct trace_seq *s = &iter->seq;
1029
1030         trace_assign_type(field, iter->ent);
1031
1032         SEQ_PUT_FIELD(s, field->prev_pid);
1033         SEQ_PUT_FIELD(s, field->prev_prio);
1034         SEQ_PUT_FIELD(s, field->prev_state);
1035         SEQ_PUT_FIELD(s, field->next_cpu);
1036         SEQ_PUT_FIELD(s, field->next_pid);
1037         SEQ_PUT_FIELD(s, field->next_prio);
1038         SEQ_PUT_FIELD(s, field->next_state);
1039
1040         return trace_handle_return(s);
1041 }
1042
1043 static struct trace_event_functions trace_ctx_funcs = {
1044         .trace          = trace_ctx_print,
1045         .raw            = trace_ctx_raw,
1046         .hex            = trace_ctx_hex,
1047         .binary         = trace_ctxwake_bin,
1048 };
1049
1050 static struct trace_event trace_ctx_event = {
1051         .type           = TRACE_CTX,
1052         .funcs          = &trace_ctx_funcs,
1053 };
1054
1055 static struct trace_event_functions trace_wake_funcs = {
1056         .trace          = trace_wake_print,
1057         .raw            = trace_wake_raw,
1058         .hex            = trace_wake_hex,
1059         .binary         = trace_ctxwake_bin,
1060 };
1061
1062 static struct trace_event trace_wake_event = {
1063         .type           = TRACE_WAKE,
1064         .funcs          = &trace_wake_funcs,
1065 };
1066
1067 /* TRACE_STACK */
1068
1069 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1070                                            int flags, struct trace_event *event)
1071 {
1072         struct stack_entry *field;
1073         struct trace_seq *s = &iter->seq;
1074         unsigned long *p;
1075         unsigned long *end;
1076
1077         trace_assign_type(field, iter->ent);
1078         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1079
1080         trace_seq_puts(s, "<stack trace>\n");
1081
1082         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1083
1084                 if (trace_seq_has_overflowed(s))
1085                         break;
1086
1087                 trace_seq_puts(s, " => ");
1088                 seq_print_ip_sym(s, *p, flags);
1089                 trace_seq_putc(s, '\n');
1090         }
1091
1092         return trace_handle_return(s);
1093 }
1094
1095 static struct trace_event_functions trace_stack_funcs = {
1096         .trace          = trace_stack_print,
1097 };
1098
1099 static struct trace_event trace_stack_event = {
1100         .type           = TRACE_STACK,
1101         .funcs          = &trace_stack_funcs,
1102 };
1103
1104 /* TRACE_USER_STACK */
1105 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1106                                                 int flags, struct trace_event *event)
1107 {
1108         struct trace_array *tr = iter->tr;
1109         struct userstack_entry *field;
1110         struct trace_seq *s = &iter->seq;
1111         struct mm_struct *mm = NULL;
1112         unsigned int i;
1113
1114         trace_assign_type(field, iter->ent);
1115
1116         trace_seq_puts(s, "<user stack trace>\n");
1117
1118         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1119                 struct task_struct *task;
1120                 /*
1121                  * we do the lookup on the thread group leader,
1122                  * since individual threads might have already quit!
1123                  */
1124                 rcu_read_lock();
1125                 task = find_task_by_vpid(field->tgid);
1126                 if (task)
1127                         mm = get_task_mm(task);
1128                 rcu_read_unlock();
1129         }
1130
1131         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1132                 unsigned long ip = field->caller[i];
1133
1134                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1135                         break;
1136
1137                 trace_seq_puts(s, " => ");
1138
1139                 if (!ip) {
1140                         trace_seq_puts(s, "??");
1141                         trace_seq_putc(s, '\n');
1142                         continue;
1143                 }
1144
1145                 seq_print_user_ip(s, mm, ip, flags);
1146                 trace_seq_putc(s, '\n');
1147         }
1148
1149         if (mm)
1150                 mmput(mm);
1151
1152         return trace_handle_return(s);
1153 }
1154
1155 static struct trace_event_functions trace_user_stack_funcs = {
1156         .trace          = trace_user_stack_print,
1157 };
1158
1159 static struct trace_event trace_user_stack_event = {
1160         .type           = TRACE_USER_STACK,
1161         .funcs          = &trace_user_stack_funcs,
1162 };
1163
1164 /* TRACE_HWLAT */
1165 static enum print_line_t
1166 trace_hwlat_print(struct trace_iterator *iter, int flags,
1167                   struct trace_event *event)
1168 {
1169         struct trace_entry *entry = iter->ent;
1170         struct trace_seq *s = &iter->seq;
1171         struct hwlat_entry *field;
1172
1173         trace_assign_type(field, entry);
1174
1175         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
1176                          field->seqnum,
1177                          field->duration,
1178                          field->outer_duration,
1179                          (long long)field->timestamp.tv_sec,
1180                          field->timestamp.tv_nsec);
1181
1182         if (field->nmi_count) {
1183                 /*
1184                  * The generic sched_clock() is not NMI safe, thus
1185                  * we only record the count and not the time.
1186                  */
1187                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1188                         trace_seq_printf(s, " nmi-total:%llu",
1189                                          field->nmi_total_ts);
1190                 trace_seq_printf(s, " nmi-count:%u",
1191                                  field->nmi_count);
1192         }
1193
1194         trace_seq_putc(s, '\n');
1195
1196         return trace_handle_return(s);
1197 }
1198
1199
1200 static enum print_line_t
1201 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1202                 struct trace_event *event)
1203 {
1204         struct hwlat_entry *field;
1205         struct trace_seq *s = &iter->seq;
1206
1207         trace_assign_type(field, iter->ent);
1208
1209         trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1210                          field->duration,
1211                          field->outer_duration,
1212                          (long long)field->timestamp.tv_sec,
1213                          field->timestamp.tv_nsec,
1214                          field->seqnum);
1215
1216         return trace_handle_return(s);
1217 }
1218
1219 static struct trace_event_functions trace_hwlat_funcs = {
1220         .trace          = trace_hwlat_print,
1221         .raw            = trace_hwlat_raw,
1222 };
1223
1224 static struct trace_event trace_hwlat_event = {
1225         .type           = TRACE_HWLAT,
1226         .funcs          = &trace_hwlat_funcs,
1227 };
1228
1229 /* TRACE_BPUTS */
1230 static enum print_line_t
1231 trace_bputs_print(struct trace_iterator *iter, int flags,
1232                    struct trace_event *event)
1233 {
1234         struct trace_entry *entry = iter->ent;
1235         struct trace_seq *s = &iter->seq;
1236         struct bputs_entry *field;
1237
1238         trace_assign_type(field, entry);
1239
1240         seq_print_ip_sym(s, field->ip, flags);
1241         trace_seq_puts(s, ": ");
1242         trace_seq_puts(s, field->str);
1243
1244         return trace_handle_return(s);
1245 }
1246
1247
1248 static enum print_line_t
1249 trace_bputs_raw(struct trace_iterator *iter, int flags,
1250                 struct trace_event *event)
1251 {
1252         struct bputs_entry *field;
1253         struct trace_seq *s = &iter->seq;
1254
1255         trace_assign_type(field, iter->ent);
1256
1257         trace_seq_printf(s, ": %lx : ", field->ip);
1258         trace_seq_puts(s, field->str);
1259
1260         return trace_handle_return(s);
1261 }
1262
1263 static struct trace_event_functions trace_bputs_funcs = {
1264         .trace          = trace_bputs_print,
1265         .raw            = trace_bputs_raw,
1266 };
1267
1268 static struct trace_event trace_bputs_event = {
1269         .type           = TRACE_BPUTS,
1270         .funcs          = &trace_bputs_funcs,
1271 };
1272
1273 /* TRACE_BPRINT */
1274 static enum print_line_t
1275 trace_bprint_print(struct trace_iterator *iter, int flags,
1276                    struct trace_event *event)
1277 {
1278         struct trace_entry *entry = iter->ent;
1279         struct trace_seq *s = &iter->seq;
1280         struct bprint_entry *field;
1281
1282         trace_assign_type(field, entry);
1283
1284         seq_print_ip_sym(s, field->ip, flags);
1285         trace_seq_puts(s, ": ");
1286         trace_seq_bprintf(s, field->fmt, field->buf);
1287
1288         return trace_handle_return(s);
1289 }
1290
1291
1292 static enum print_line_t
1293 trace_bprint_raw(struct trace_iterator *iter, int flags,
1294                  struct trace_event *event)
1295 {
1296         struct bprint_entry *field;
1297         struct trace_seq *s = &iter->seq;
1298
1299         trace_assign_type(field, iter->ent);
1300
1301         trace_seq_printf(s, ": %lx : ", field->ip);
1302         trace_seq_bprintf(s, field->fmt, field->buf);
1303
1304         return trace_handle_return(s);
1305 }
1306
1307 static struct trace_event_functions trace_bprint_funcs = {
1308         .trace          = trace_bprint_print,
1309         .raw            = trace_bprint_raw,
1310 };
1311
1312 static struct trace_event trace_bprint_event = {
1313         .type           = TRACE_BPRINT,
1314         .funcs          = &trace_bprint_funcs,
1315 };
1316
1317 /* TRACE_PRINT */
1318 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1319                                            int flags, struct trace_event *event)
1320 {
1321         struct print_entry *field;
1322         struct trace_seq *s = &iter->seq;
1323
1324         trace_assign_type(field, iter->ent);
1325
1326         seq_print_ip_sym(s, field->ip, flags);
1327         trace_seq_printf(s, ": %s", field->buf);
1328
1329         return trace_handle_return(s);
1330 }
1331
1332 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1333                                          struct trace_event *event)
1334 {
1335         struct print_entry *field;
1336
1337         trace_assign_type(field, iter->ent);
1338
1339         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1340
1341         return trace_handle_return(&iter->seq);
1342 }
1343
1344 static struct trace_event_functions trace_print_funcs = {
1345         .trace          = trace_print_print,
1346         .raw            = trace_print_raw,
1347 };
1348
1349 static struct trace_event trace_print_event = {
1350         .type           = TRACE_PRINT,
1351         .funcs          = &trace_print_funcs,
1352 };
1353
1354 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1355                                          struct trace_event *event)
1356 {
1357         struct raw_data_entry *field;
1358         int i;
1359
1360         trace_assign_type(field, iter->ent);
1361
1362         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1363
1364         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1365                 trace_seq_printf(&iter->seq, " %02x",
1366                                  (unsigned char)field->buf[i]);
1367
1368         trace_seq_putc(&iter->seq, '\n');
1369
1370         return trace_handle_return(&iter->seq);
1371 }
1372
1373 static struct trace_event_functions trace_raw_data_funcs = {
1374         .trace          = trace_raw_data,
1375         .raw            = trace_raw_data,
1376 };
1377
1378 static struct trace_event trace_raw_data_event = {
1379         .type           = TRACE_RAW_DATA,
1380         .funcs          = &trace_raw_data_funcs,
1381 };
1382
1383
1384 static struct trace_event *events[] __initdata = {
1385         &trace_fn_event,
1386         &trace_ctx_event,
1387         &trace_wake_event,
1388         &trace_stack_event,
1389         &trace_user_stack_event,
1390         &trace_bputs_event,
1391         &trace_bprint_event,
1392         &trace_print_event,
1393         &trace_hwlat_event,
1394         &trace_raw_data_event,
1395         NULL
1396 };
1397
1398 __init static int init_events(void)
1399 {
1400         struct trace_event *event;
1401         int i, ret;
1402
1403         for (i = 0; events[i]; i++) {
1404                 event = events[i];
1405
1406                 ret = register_trace_event(event);
1407                 if (!ret) {
1408                         printk(KERN_WARNING "event %d failed to register\n",
1409                                event->type);
1410                         WARN_ON_ONCE(1);
1411                 }
1412         }
1413
1414         return 0;
1415 }
1416 early_initcall(init_events);